!3791 modelzoo: repair vgg distribute training problem

Merge pull request !3791 from ms_yan/vgg_8p_D

model_zoo/official/cv/vgg16/scripts/run_distribute_train.sh

@@ -47,6 +47,6 @@ do
     cd ./train_parallel$i || exit
     echo "start training for rank $RANK_ID, device $DEVICE_ID"
     env > env.log
-    python train.py --data_path=$2 --device_target="Ascend" --device_id=$i &> log &
+    python train.py --data_path=$2 --device_target="Ascend" --device_id=$i --is_distributed=1 &> log &
     cd ..
 done

model_zoo/official/cv/vgg16/train.py

@@ -191,12 +191,13 @@ if __name__ == '__main__':
     if args.is_distributed:
         if args.device_target == "Ascend":
             init()
+            context.set_context(device_id=args.device_id)
         elif args.device_target == "GPU":
             init("nccl")
-            args.rank = get_rank()
-            args.group_size = get_group_size()
-            device_num = args.group_size
 
+        args.rank = get_rank()
+        args.group_size = get_group_size()
+        device_num = args.group_size
         context.reset_auto_parallel_context()
         context.set_auto_parallel_context(device_num=device_num, parallel_mode=ParallelMode.DATA_PARALLEL,
                                           mirror_mean=True)